Marrucciite is an extremely rare sulfosalt mineral primarily known from the Jas Roux locality in France. It typically occurs as small metallic, lead-gray grains associated with other sulfide and sulfosalt minerals in hydrothermal deposits.
Is this marrucciite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch marrucciite with a known reference. Marrucciite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Marrucciite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Marrucciite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: lead-gray, black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: anhedral to subhedral grains.
Often confused with
Marrucciite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Marrucciite leaves black, Galena leaves lead-gray.
How to tell apart: Streak differs — Marrucciite leaves black, Cinnabar leaves scarlet; luster reads metallic on Marrucciite and adamantine on Cinnabar.
How to tell apart: Streak differs — Marrucciite leaves black, Stibnite leaves lead-gray.
Often found alongside marrucciite
Minerals reported to co-occur with marrucciite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Hg₃Pb₄Sb₆S₁₄
- Mohs hardness
- 2
- Density
- 6.35 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Anhedral to Subhedral Grains
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Veins in Sedimentary or Metamorphic Rocks
- Typical price
- $50-300 per specimen
Where rockhounds find marrucciite
Classic worldwide localities
- Jas Roux, Hautes-Alpes, France
Field-hunting tip
Look in hydrothermal veins in sedimentary or metamorphic rocks country — that is the host setting where marrucciite typically forms. If you start seeing cinnabar, stibnite, pyrite in float, you are in the right ground. Field specimens usually show a anhedral to subhedral grains habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify marrucciite?+
Where is marrucciite found?+
How much is marrucciite worth?+
Is marrucciite safe to handle?+
What rocks look like marrucciite?+
What minerals are found with marrucciite?+
What kind of rock does marrucciite form in?+
What is marrucciite used for?+
Find marrucciite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
